<?php

/**
 * Class representing phpQuery objects.
 *
 * @author Tobiasz Cudnik <tobiasz.cudnik/gmail.com>
 * @package phpQuery
 * @method phpQueryObject clone() clone()
 * @method phpQueryObject empty() empty()
 * @method phpQueryObject next() next($selector = null)
 * @method phpQueryObject prev() prev($selector = null)
 * @property Int $length
 */
class phpQueryObject implements Iterator, Countable, ArrayAccess {

    public $documentID = null;

    /**
     * DOMDocument class.
     *
     * @var DOMDocument
     */
    public $document = null;
    public $charset = null;

    /**
     *
     * @var DOMDocumentWrapper
     */
    public $documentWrapper = null;

    /**
     * XPath interface.
     *
     * @var DOMXPath
     */
    public $xpath = null;

    /**
     * Stack of selected elements.
     * @TODO refactor to ->nodes
     * @var array
     */
    public $elements = array();

    /**
     * @access private
     */
    protected $elementsBackup = array();

    /**
     * @access private
     */
    protected $previous = null;

    /**
     * @access private
     * @TODO deprecate
     */
    protected $root = array();

    /**
     * Indicated if doument is just a fragment (no <html> tag).
     *
     * Every document is realy a full document, so even documentFragments can
     * be queried against <html>, but getDocument(id)->htmlOuter() will return
     * only contents of <body>.
     *
     * @var bool
     */
    public $documentFragment = true;

    /**
     * Iterator interface helper
     * @access private
     */
    protected $elementsInterator = array();

    /**
     * Iterator interface helper
     * @access private
     */
    protected $valid = false;

    /**
     * Iterator interface helper
     * @access private
     */
    protected $current = null;

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function __construct($documentID) {
//		if ($documentID instanceof self)
//			var_dump($documentID->getDocumentID());
        $id = $documentID instanceof self ? $documentID->getDocumentID() : $documentID;
//		var_dump($id);
        if (!isset(phpQuery::$documents[$id])) {
//			var_dump(phpQuery::$documents);
            throw new Exception("Document with ID '{$id}' isn't loaded. Use phpQuery::newDocument(\$html) or phpQuery::newDocumentFile(\$file) first.");
        }
        $this->documentID = $id;
        $this->documentWrapper = & phpQuery::$documents[$id];
        $this->document = & $this->documentWrapper->document;
        $this->xpath = & $this->documentWrapper->xpath;
        $this->charset = & $this->documentWrapper->charset;
        $this->documentFragment = & $this->documentWrapper->isDocumentFragment;
        // TODO check $this->DOM->documentElement;
//		$this->root = $this->document->documentElement;
        $this->root = & $this->documentWrapper->root;
//		$this->toRoot();
        $this->elements = array($this->root);
    }

    /**
     *
     * @access private
     * @param $attr
     * @return unknown_type
     */
    public function __get($attr) {
        switch ($attr) {
            // FIXME doesnt work at all ?
            case 'length':
                return $this->size();
                break;
            default:
                return $this->$attr;
        }
    }

    /**
     * Saves actual object to $var by reference.
     * Useful when need to break chain.
     * @param phpQueryObject $var
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function toReference(&$var) {
        return $var = $this;
    }

    public function documentFragment($state = null) {
        if ($state) {
            phpQuery::$documents[$this->getDocumentID()]['documentFragment'] = $state;
            return $this;
        }
        return $this->documentFragment;
    }

    /**
     * @access private
     * @TODO documentWrapper
     */
    protected function isRoot($node) {
//		return $node instanceof DOMDOCUMENT || $node->tagName == 'html';
        return $node instanceof DOMDOCUMENT || ($node instanceof DOMELEMENT && $node->tagName == 'html') || $this->root->isSameNode($node);
    }

    /**
     * @access private
     */
    protected function stackIsRoot() {
        return $this->size() == 1 && $this->isRoot($this->elements[0]);
    }

    /**
     * Enter description here...
     * NON JQUERY METHOD
     *
     * Watch out, it doesn't creates new instance, can be reverted with end().
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function toRoot() {
        $this->elements = array($this->root);
        return $this;
//		return $this->newInstance(array($this->root));
    }

    /**
     * Saves object's DocumentID to $var by reference.
     * <code>
     * $myDocumentId;
     * phpQuery::newDocument('<div/>')
     *     ->getDocumentIDRef($myDocumentId)
     *     ->find('div')->...
     * </code>
     *
     * @param unknown_type $domId
     * @see phpQuery::newDocument
     * @see phpQuery::newDocumentFile
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function getDocumentIDRef(&$documentID) {
        $documentID = $this->getDocumentID();
        return $this;
    }

    /**
     * Returns object with stack set to document root.
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function getDocument() {
        return phpQuery::getDocument($this->getDocumentID());
    }

    /**
     *
     * @return DOMDocument
     */
    public function getDOMDocument() {
        return $this->document;
    }

    /**
     * Get object's Document ID.
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function getDocumentID() {
        return $this->documentID;
    }

    /**
     * Unloads whole document from memory.
     * CAUTION! None further operations will be possible on this document.
     * All objects refering to it will be useless.
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function unloadDocument() {
        phpQuery::unloadDocuments($this->getDocumentID());
    }

    public function isHTML() {
        return $this->documentWrapper->isHTML;
    }

    public function isXHTML() {
        return $this->documentWrapper->isXHTML;
    }

    public function isXML() {
        return $this->documentWrapper->isXML;
    }

    /**
     * Enter description here...
     *
     * @link http://docs.jquery.com/Ajax/serialize
     * @return string
     */
    public function serialize() {
        return phpQuery::param($this->serializeArray());
    }

    /**
     * Enter description here...
     *
     * @link http://docs.jquery.com/Ajax/serializeArray
     * @return array
     */
    public function serializeArray($submit = null) {
        $source = $this->filter('form, input, select, textarea')
                ->find('input, select, textarea')
                ->andSelf()
                ->not('form');
        $return = array();
//		$source->dumpDie();
        foreach ($source as $input) {
            $input = phpQuery::pq($input);
            if ($input->is('[disabled]'))
                continue;
            if (!$input->is('[name]'))
                continue;
            if ($input->is('[type=checkbox]') && !$input->is('[checked]'))
                continue;
            // jquery diff
            if ($submit && $input->is('[type=submit]')) {
                if ($submit instanceof DOMELEMENT && !$input->elements[0]->isSameNode($submit))
                    continue;
                else if (is_string($submit) && $input->attr('name') != $submit)
                    continue;
            }
            $return[] = array(
                'name' => $input->attr('name'),
                'value' => $input->val(),
            );
        }
        return $return;
    }

    /**
     * @access private
     */
    protected function debug($in) {
        if (!phpQuery::$debug)
            return;
        print('<pre>');
        print_r($in);
        // file debug
//		file_put_contents(dirname(__FILE__).'/phpQuery.log', print_r($in, true)."\n", FILE_APPEND);
        // quite handy debug trace
//		if ( is_array($in))
//			print_r(array_slice(debug_backtrace(), 3));
        print("</pre>\n");
    }

    /**
     * @access private
     */
    protected function isRegexp($pattern) {
        return in_array(
                $pattern[mb_strlen($pattern) - 1], array('^', '*', '$')
        );
    }

    /**
     * Determines if $char is really a char.
     *
     * @param string $char
     * @return bool
     * @todo rewrite me to charcode range ! ;)
     * @access private
     */
    protected function isChar($char) {
        return extension_loaded('mbstring') && phpQuery::$mbstringSupport ? mb_eregi('\w', $char) : preg_match('@\w@', $char);
    }

    /**
     * @access private
     */
    protected function parseSelector($query) {
        // clean spaces
        // TODO include this inside parsing ?
        $query = trim(
                preg_replace('@\s+@', ' ', preg_replace('@\s*(>|\\+|~)\s*@', '\\1', $query)
                )
        );
        $queries = array(array());
        if (!$query)
            return $queries;
        $return = & $queries[0];
        $specialChars = array('>', ' ');
//		$specialCharsMapping = array('/' => '>');
        $specialCharsMapping = array();
        $strlen = mb_strlen($query);
        $classChars = array('.', '-');
        $pseudoChars = array('-');
        $tagChars = array('*', '|', '-');
        // split multibyte string
        // http://code.google.com/p/phpquery/issues/detail?id=76
        $_query = array();
        for ($i = 0; $i < $strlen; $i++)
            $_query[] = mb_substr($query, $i, 1);
        $query = $_query;
        // it works, but i dont like it...
        $i = 0;
        while ($i < $strlen) {
            $c = $query[$i];
            $tmp = '';
            // TAG
            if ($this->isChar($c) || in_array($c, $tagChars)) {
                while (isset($query[$i]) && ($this->isChar($query[$i]) || in_array($query[$i], $tagChars))) {
                    $tmp .= $query[$i];
                    $i++;
                }
                $return[] = $tmp;
                // IDs
            } else if ($c == '#') {
                $i++;
                while (isset($query[$i]) && ($this->isChar($query[$i]) || $query[$i] == '-')) {
                    $tmp .= $query[$i];
                    $i++;
                }
                $return[] = '#' . $tmp;
                // SPECIAL CHARS
            } else if (in_array($c, $specialChars)) {
                $return[] = $c;
                $i++;
                // MAPPED SPECIAL MULTICHARS
//			} else if ( $c.$query[$i+1] == '//') {
//				$return[] = ' ';
//				$i = $i+2;
                // MAPPED SPECIAL CHARS
            } else if (isset($specialCharsMapping[$c])) {
                $return[] = $specialCharsMapping[$c];
                $i++;
                // COMMA
            } else if ($c == ',') {
                $queries[] = array();
                $return = & $queries[count($queries) - 1];
                $i++;
                while (isset($query[$i]) && $query[$i] == ' ')
                    $i++;
                // CLASSES
            } else if ($c == '.') {
                while (isset($query[$i]) && ($this->isChar($query[$i]) || in_array($query[$i], $classChars))) {
                    $tmp .= $query[$i];
                    $i++;
                }
                $return[] = $tmp;
                // ~ General Sibling Selector
            } else if ($c == '~') {
                $spaceAllowed = true;
                $tmp .= $query[$i++];
                while (isset($query[$i]) && ($this->isChar($query[$i]) || in_array($query[$i], $classChars) || $query[$i] == '*' || ($query[$i] == ' ' && $spaceAllowed)
                )) {
                    if ($query[$i] != ' ')
                        $spaceAllowed = false;
                    $tmp .= $query[$i];
                    $i++;
                }
                $return[] = $tmp;
                // + Adjacent sibling selectors
            } else if ($c == '+') {
                $spaceAllowed = true;
                $tmp .= $query[$i++];
                while (isset($query[$i]) && ($this->isChar($query[$i]) || in_array($query[$i], $classChars) || $query[$i] == '*' || ($spaceAllowed && $query[$i] == ' ')
                )) {
                    if ($query[$i] != ' ')
                        $spaceAllowed = false;
                    $tmp .= $query[$i];
                    $i++;
                }
                $return[] = $tmp;
                // ATTRS
            } else if ($c == '[') {
                $stack = 1;
                $tmp .= $c;
                while (isset($query[++$i])) {
                    $tmp .= $query[$i];
                    if ($query[$i] == '[') {
                        $stack++;
                    } else if ($query[$i] == ']') {
                        $stack--;
                        if (!$stack)
                            break;
                    }
                }
                $return[] = $tmp;
                $i++;
                // PSEUDO CLASSES
            } else if ($c == ':') {
                $stack = 1;
                $tmp .= $query[$i++];
                while (isset($query[$i]) && ($this->isChar($query[$i]) || in_array($query[$i], $pseudoChars))) {
                    $tmp .= $query[$i];
                    $i++;
                }
                // with arguments ?
                if (isset($query[$i]) && $query[$i] == '(') {
                    $tmp .= $query[$i];
                    $stack = 1;
                    while (isset($query[++$i])) {
                        $tmp .= $query[$i];
                        if ($query[$i] == '(') {
                            $stack++;
                        } else if ($query[$i] == ')') {
                            $stack--;
                            if (!$stack)
                                break;
                        }
                    }
                    $return[] = $tmp;
                    $i++;
                } else {
                    $return[] = $tmp;
                }
            } else {
                $i++;
            }
        }
        foreach ($queries as $k => $q) {
            if (isset($q[0])) {
                if (isset($q[0][0]) && $q[0][0] == ':')
                    array_unshift($queries[$k], '*');
                if ($q[0] != '>')
                    array_unshift($queries[$k], ' ');
            }
        }
        return $queries;
    }

    /**
     * Return matched DOM nodes.
     *
     * @param int $index
     * @return array|DOMElement Single DOMElement or array of DOMElement.
     */
    public function get($index = null, $callback1 = null, $callback2 = null, $callback3 = null) {
        $return = isset($index) ? (isset($this->elements[$index]) ? $this->elements[$index] : null) : $this->elements;
        // pass thou callbacks
        $args = func_get_args();
        $args = array_slice($args, 1);
        foreach ($args as $callback) {
            if (is_array($return))
                foreach ($return as $k => $v)
                    $return[$k] = phpQuery::callbackRun($callback, array($v));
            else
                $return = phpQuery::callbackRun($callback, array($return));
        }
        return $return;
    }

    /**
     * Return matched DOM nodes.
     * jQuery difference.
     *
     * @param int $index
     * @return array|string Returns string if $index != null
     * @todo implement callbacks
     * @todo return only arrays ?
     * @todo maybe other name...
     */
    public function getString($index = null, $callback1 = null, $callback2 = null, $callback3 = null) {
        if ($index)
            $return = $this->eq($index)->text();
        else {
            $return = array();
            for ($i = 0; $i < $this->size(); $i++) {
                $return[] = $this->eq($i)->text();
            }
        }
        // pass thou callbacks
        $args = func_get_args();
        $args = array_slice($args, 1);
        foreach ($args as $callback) {
            $return = phpQuery::callbackRun($callback, array($return));
        }
        return $return;
    }

    /**
     * Return matched DOM nodes.
     * jQuery difference.
     *
     * @param int $index
     * @return array|string Returns string if $index != null
     * @todo implement callbacks
     * @todo return only arrays ?
     * @todo maybe other name...
     */
    public function getStrings($index = null, $callback1 = null, $callback2 = null, $callback3 = null) {
        if ($index)
            $return = $this->eq($index)->text();
        else {
            $return = array();
            for ($i = 0; $i < $this->size(); $i++) {
                $return[] = $this->eq($i)->text();
            }
            // pass thou callbacks
            $args = func_get_args();
            $args = array_slice($args, 1);
        }
        foreach ($args as $callback) {
            if (is_array($return))
                foreach ($return as $k => $v)
                    $return[$k] = phpQuery::callbackRun($callback, array($v));
            else
                $return = phpQuery::callbackRun($callback, array($return));
        }
        return $return;
    }

    /**
     * Returns new instance of actual class.
     *
     * @param array $newStack Optional. Will replace old stack with new and move old one to history.c
     */
    public function newInstance($newStack = null) {
        $class = get_class($this);
        // support inheritance by passing old object to overloaded constructor
        $new = $class != 'phpQuery' ? new $class($this, $this->getDocumentID()) : new phpQueryObject($this->getDocumentID());
        $new->previous = $this;
        if (is_null($newStack)) {
            $new->elements = $this->elements;
            if ($this->elementsBackup)
                $this->elements = $this->elementsBackup;
        } else if (is_string($newStack)) {
            $new->elements = phpQuery::pq($newStack, $this->getDocumentID())->stack();
        } else {
            $new->elements = $newStack;
        }
        return $new;
    }

    /**
     * Enter description here...
     *
     * In the future, when PHP will support XLS 2.0, then we would do that this way:
     * contains(tokenize(@class, '\s'), "something")
     * @param unknown_type $class
     * @param unknown_type $node
     * @return boolean
     * @access private
     */
    protected function matchClasses($class, $node) {
        // multi-class
        if (mb_strpos($class, '.', 1)) {
            $classes = explode('.', substr($class, 1));
            $classesCount = count($classes);
            $nodeClasses = explode(' ', $node->getAttribute('class'));
            $nodeClassesCount = count($nodeClasses);
            if ($classesCount > $nodeClassesCount)
                return false;
            $diff = count(
                    array_diff(
                            $classes, $nodeClasses
                    )
            );
            if (!$diff)
                return true;
            // single-class
        } else {
            return in_array(
                    // strip leading dot from class name
                    substr($class, 1),
                    // get classes for element as array
                    explode(' ', $node->getAttribute('class'))
            );
        }
    }

    /**
     * @access private
     */
    protected function runQuery($XQuery, $selector = null, $compare = null) {
        if ($compare && !method_exists($this, $compare))
            return false;
        $stack = array();
        if (!$this->elements)
            $this->debug('Stack empty, skipping...');
//		var_dump($this->elements[0]->nodeType);
        // element, document
        foreach ($this->stack(array(1, 9, 13)) as $k => $stackNode) {
            $detachAfter = false;
            // to work on detached nodes we need temporary place them somewhere
            // thats because context xpath queries sucks ;]
            $testNode = $stackNode;
            while ($testNode) {
                if (!$testNode->parentNode && !$this->isRoot($testNode)) {
                    $this->root->appendChild($testNode);
                    $detachAfter = $testNode;
                    break;
                }
                $testNode = isset($testNode->parentNode) ? $testNode->parentNode : null;
            }
            // XXX tmp ?
            $xpath = $this->documentWrapper->isXHTML ? $this->getNodeXpath($stackNode, 'html') : $this->getNodeXpath($stackNode);
            // FIXME pseudoclasses-only query, support XML
            $query = $XQuery == '//' && $xpath == '/html[1]' ? '//*' : $xpath . $XQuery;
            $this->debug("XPATH: {$query}");
            // run query, get elements
            $nodes = $this->xpath->query($query);
            $this->debug("QUERY FETCHED");
            if (!$nodes->length)
                $this->debug('Nothing found');
            $debug = array();
            foreach ($nodes as $node) {
                $matched = false;
                if ($compare) {
                    phpQuery::$debug ?
                                    $this->debug("Found: " . $this->whois($node) . ", comparing with {$compare}()") : null;
                    $phpQueryDebug = phpQuery::$debug;
                    phpQuery::$debug = false;
                    // TODO ??? use phpQuery::callbackRun()
                    if (call_user_func_array(array($this, $compare), array($selector, $node)))
                        $matched = true;
                    phpQuery::$debug = $phpQueryDebug;
                } else {
                    $matched = true;
                }
                if ($matched) {
                    if (phpQuery::$debug)
                        $debug[] = $this->whois($node);
                    $stack[] = $node;
                }
            }
            if (phpQuery::$debug) {
                $this->debug("Matched " . count($debug) . ": " . implode(', ', $debug));
            }
            if ($detachAfter)
                $this->root->removeChild($detachAfter);
        }
        $this->elements = $stack;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function find($selectors, $context = null, $noHistory = false) {
        if (!$noHistory)
        // backup last stack /for end()/
            $this->elementsBackup = $this->elements;
        // allow to define context
        // TODO combine code below with phpQuery::pq() context guessing code
        //   as generic function
        if ($context) {
            if (!is_array($context) && $context instanceof DOMELEMENT)
                $this->elements = array($context);
            else if (is_array($context)) {
                $this->elements = array();
                foreach ($context as $c)
                    if ($c instanceof DOMELEMENT)
                        $this->elements[] = $c;
            } else if ($context instanceof self)
                $this->elements = $context->elements;
        }
        $queries = $this->parseSelector($selectors);
        $this->debug(array('FIND', $selectors, $queries));
        $XQuery = '';
        // remember stack state because of multi-queries
        $oldStack = $this->elements;
        // here we will be keeping found elements
        $stack = array();
        foreach ($queries as $selector) {
            $this->elements = $oldStack;
            $delimiterBefore = false;
            foreach ($selector as $s) {
                // TAG
                $isTag = extension_loaded('mbstring') && phpQuery::$mbstringSupport ? mb_ereg_match('^[\w|\||-]+$', $s) || $s == '*' : preg_match('@^[\w|\||-]+$@', $s) || $s == '*';
                if ($isTag) {
                    if ($this->isXML()) {
                        // namespace support
                        if (mb_strpos($s, '|') !== false) {
                            $ns = $tag = null;
                            list($ns, $tag) = explode('|', $s);
                            $XQuery .= "$ns:$tag";
                        } else if ($s == '*') {
                            $XQuery .= "*";
                        } else {
                            $XQuery .= "*[local-name()='$s']";
                        }
                    } else {
                        $XQuery .= $s;
                    }
                    // ID
                } else if ($s[0] == '#') {
                    if ($delimiterBefore)
                        $XQuery .= '*';
                    $XQuery .= "[@id='" . substr($s, 1) . "']";
                    // ATTRIBUTES
                } else if ($s[0] == '[') {
                    if ($delimiterBefore)
                        $XQuery .= '*';
                    // strip side brackets
                    $attr = trim($s, '][');
                    $execute = false;
                    // attr with specifed value
                    if (mb_strpos($s, '=')) {
                        $value = null;
                        list($attr, $value) = explode('=', $attr);
                        $value = trim($value, "'\"");
                        if ($this->isRegexp($attr)) {
                            // cut regexp character
                            $attr = substr($attr, 0, -1);
                            $execute = true;
                            $XQuery .= "[@{$attr}]";
                        } else {
                            $XQuery .= "[@{$attr}='{$value}']";
                        }
                        // attr without specified value
                    } else {
                        $XQuery .= "[@{$attr}]";
                    }
                    if ($execute) {
                        $this->runQuery($XQuery, $s, 'is');
                        $XQuery = '';
                        if (!$this->length())
                            break;
                    }
                    // CLASSES
                } else if ($s[0] == '.') {
                    // TODO use return $this->find("./self::*[contains(concat(\" \",@class,\" \"), \" $class \")]");
                    // thx wizDom ;)
                    if ($delimiterBefore)
                        $XQuery .= '*';
                    $XQuery .= '[@class]';
                    $this->runQuery($XQuery, $s, 'matchClasses');
                    $XQuery = '';
                    if (!$this->length())
                        break;
                    // ~ General Sibling Selector
                } else if ($s[0] == '~') {
                    $this->runQuery($XQuery);
                    $XQuery = '';
                    $this->elements = $this
                                    ->siblings(
                                            substr($s, 1)
                                    )->elements;
                    if (!$this->length())
                        break;
                    // + Adjacent sibling selectors
                } else if ($s[0] == '+') {
                    // TODO /following-sibling::
                    $this->runQuery($XQuery);
                    $XQuery = '';
                    $subSelector = substr($s, 1);
                    $subElements = $this->elements;
                    $this->elements = array();
                    foreach ($subElements as $node) {
                        // search first DOMElement sibling
                        $test = $node->nextSibling;
                        while ($test && !($test instanceof DOMELEMENT))
                            $test = $test->nextSibling;
                        if ($test && $this->is($subSelector, $test))
                            $this->elements[] = $test;
                    }
                    if (!$this->length())
                        break;
                    // PSEUDO CLASSES
                } else if ($s[0] == ':') {
                    // TODO optimization for :first :last
                    if ($XQuery) {
                        $this->runQuery($XQuery);
                        $XQuery = '';
                    }
                    if (!$this->length())
                        break;
                    $this->pseudoClasses($s);
                    if (!$this->length())
                        break;
                    // DIRECT DESCENDANDS
                } else if ($s == '>') {
                    $XQuery .= '/';
                    $delimiterBefore = 2;
                    // ALL DESCENDANDS
                } else if ($s == ' ') {
                    $XQuery .= '//';
                    $delimiterBefore = 2;
                    // ERRORS
                } else {
                    phpQuery::debug("Unrecognized token '$s'");
                }
                $delimiterBefore = $delimiterBefore === 2;
            }
            // run query if any
            if ($XQuery && $XQuery != '//') {
                $this->runQuery($XQuery);
                $XQuery = '';
            }
            foreach ($this->elements as $node)
                if (!$this->elementsContainsNode($node, $stack))
                    $stack[] = $node;
        }
        $this->elements = $stack;
        return $this->newInstance();
    }

    /**
     * @todo create API for classes with pseudoselectors
     * @access private
     */
    protected function pseudoClasses($class) {
        // TODO clean args parsing ?
        $class = ltrim($class, ':');
        $haveArgs = mb_strpos($class, '(');
        if ($haveArgs !== false) {
            $args = substr($class, $haveArgs + 1, -1);
            $class = substr($class, 0, $haveArgs);
        }
        switch ($class) {
            case 'even':
            case 'odd':
                $stack = array();
                foreach ($this->elements as $i => $node) {
                    if ($class == 'even' && ($i % 2) == 0)
                        $stack[] = $node;
                    else if ($class == 'odd' && $i % 2)
                        $stack[] = $node;
                }
                $this->elements = $stack;
                break;
            case 'eq':
                $k = intval($args);
                $this->elements = isset($this->elements[$k]) ? array($this->elements[$k]) : array();
                break;
            case 'gt':
                $this->elements = array_slice($this->elements, $args + 1);
                break;
            case 'lt':
                $this->elements = array_slice($this->elements, 0, $args + 1);
                break;
            case 'first':
                if (isset($this->elements[0]))
                    $this->elements = array($this->elements[0]);
                break;
            case 'last':
                if ($this->elements)
                    $this->elements = array($this->elements[count($this->elements) - 1]);
                break;
            /* case 'parent':
              $stack = array();
              foreach($this->elements as $node) {
              if ( $node->childNodes->length )
              $stack[] = $node;
              }
              $this->elements = $stack;
              break; */
            case 'contains':
                $text = trim($args, "\"'");
                $stack = array();
                foreach ($this->elements as $node) {
                    if (mb_stripos($node->textContent, $text) === false)
                        continue;
                    $stack[] = $node;
                }
                $this->elements = $stack;
                break;
            case 'not':
                $selector = self::unQuote($args);
                $this->elements = $this->not($selector)->stack();
                break;
            case 'slice':
                // TODO jQuery difference ?
                $args = explode(',', str_replace(', ', ',', trim($args, "\"'"))
                );
                $start = $args[0];
                $end = isset($args[1]) ? $args[1] : null;
                if ($end > 0)
                    $end = $end - $start;
                $this->elements = array_slice($this->elements, $start, $end);
                break;
            case 'has':
                $selector = trim($args, "\"'");
                $stack = array();
                foreach ($this->stack(1) as $el) {
                    if ($this->find($selector, $el, true)->length)
                        $stack[] = $el;
                }
                $this->elements = $stack;
                break;
            case 'submit':
            case 'reset':
                $this->elements = phpQuery::merge(
                                $this->map(array($this, 'is'), "input[type=$class]", new CallbackParam()
                                ), $this->map(array($this, 'is'), "button[type=$class]", new CallbackParam()
                                )
                );
                break;
//				$stack = array();
//				foreach($this->elements as $node)
//					if ($node->is('input[type=submit]') || $node->is('button[type=submit]'))
//						$stack[] = $el;
//				$this->elements = $stack;
            case 'input':
                $this->elements = $this->map(
                                array($this, 'is'), 'input', new CallbackParam()
                        )->elements;
                break;
            case 'password':
            case 'checkbox':
            case 'radio':
            case 'hidden':
            case 'image':
            case 'file':
                $this->elements = $this->map(
                                array($this, 'is'), "input[type=$class]", new CallbackParam()
                        )->elements;
                break;
            case 'parent':
                $this->elements = $this->map(
                                create_function('$node', '
						return $node instanceof DOMELEMENT && $node->childNodes->length
							? $node : null;')
                        )->elements;
                break;
            case 'empty':
                $this->elements = $this->map(
                                create_function('$node', '
						return $node instanceof DOMELEMENT && $node->childNodes->length
							? null : $node;')
                        )->elements;
                break;
            case 'disabled':
            case 'selected':
            case 'checked':
                $this->elements = $this->map(
                                array($this, 'is'), "[$class]", new CallbackParam()
                        )->elements;
                break;
            case 'enabled':
                $this->elements = $this->map(
                                create_function('$node', '
						return pq($node)->not(":disabled") ? $node : null;')
                        )->elements;
                break;
            case 'header':
                $this->elements = $this->map(
                                create_function('$node', '$isHeader = isset($node->tagName) && in_array($node->tagName, array(
							"h1", "h2", "h3", "h4", "h5", "h6", "h7"
						));
						return $isHeader
							? $node
							: null;')
                        )->elements;
//				$this->elements = $this->map(
//					create_function('$node', '$node = pq($node);
//						return $node->is("h1")
//							|| $node->is("h2")
//							|| $node->is("h3")
//							|| $node->is("h4")
//							|| $node->is("h5")
//							|| $node->is("h6")
//							|| $node->is("h7")
//							? $node
//							: null;')
//				)->elements;
                break;
            case 'only-child':
                $this->elements = $this->map(
                                create_function('$node', 'return pq($node)->siblings()->size() == 0 ? $node : null;')
                        )->elements;
                break;
            case 'first-child':
                $this->elements = $this->map(
                                create_function('$node', 'return pq($node)->prevAll()->size() == 0 ? $node : null;')
                        )->elements;
                break;
            case 'last-child':
                $this->elements = $this->map(
                                create_function('$node', 'return pq($node)->nextAll()->size() == 0 ? $node : null;')
                        )->elements;
                break;
            case 'nth-child':
                $param = trim($args, "\"'");
                if (!$param)
                    break;
                // nth-child(n+b) to nth-child(1n+b)
                if ($param{0} == 'n')
                    $param = '1' . $param;
                // :nth-child(index/even/odd/equation)
                if ($param == 'even' || $param == 'odd')
                    $mapped = $this->map(
                            create_function('$node, $param', '$index = pq($node)->prevAll()->size()+1;
							if ($param == "even" && ($index%2) == 0)
								return $node;
							else if ($param == "odd" && $index%2 == 1)
								return $node;
							else
								return null;'), new CallbackParam(), $param
                    );
                else if (mb_strlen($param) > 1 && $param{1} == 'n')
                // an+b
                    $mapped = $this->map(
                            create_function('$node, $param', '$prevs = pq($node)->prevAll()->size();
							$index = 1+$prevs;
							$b = mb_strlen($param) > 3
								? $param{3}
								: 0;
							$a = $param{0};
							if ($b && $param{2} == "-")
								$b = -$b;
							if ($a > 0) {
								return ($index-$b)%$a == 0
									? $node
									: null;
								phpQuery::debug($a."*".floor($index/$a)."+$b-1 == ".($a*floor($index/$a)+$b-1)." ?= $prevs");
								return $a*floor($index/$a)+$b-1 == $prevs
										? $node
										: null;
							} else if ($a == 0)
								return $index == $b
										? $node
										: null;
							else
								// negative value
								return $index <= $b
										? $node
										: null;
//							if (! $b)
//								return $index%$a == 0
//									? $node
//									: null;
//							else
//								return ($index-$b)%$a == 0
//									? $node
//									: null;
							'), new CallbackParam(), $param
                    );
                else
                // index
                    $mapped = $this->map(
                            create_function('$node, $index', '$prevs = pq($node)->prevAll()->size();
							if ($prevs && $prevs == $index-1)
								return $node;
							else if (! $prevs && $index == 1)
								return $node;
							else
								return null;'), new CallbackParam(), $param
                    );
                $this->elements = $mapped->elements;
                break;
            default:
                $this->debug("Unknown pseudoclass '{$class}', skipping...");
        }
    }

    /**
     * @access private
     */
    protected function __pseudoClassParam($paramsString) {
        // TODO;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function is($selector, $nodes = null) {
        phpQuery::debug(array("Is:", $selector));
        if (!$selector)
            return false;
        $oldStack = $this->elements;
        $returnArray = false;
        if ($nodes && is_array($nodes)) {
            $this->elements = $nodes;
        } else if ($nodes)
            $this->elements = array($nodes);
        $this->filter($selector, true);
        $stack = $this->elements;
        $this->elements = $oldStack;
        if ($nodes)
            return $stack ? $stack : null;
        return (bool) count($stack);
    }

    /**
     * Enter description here...
     * jQuery difference.
     *
     * Callback:
     * - $index int
     * - $node DOMNode
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @link http://docs.jquery.com/Traversing/filter
     */
    public function filterCallback($callback, $_skipHistory = false) {
        if (!$_skipHistory) {
            $this->elementsBackup = $this->elements;
            $this->debug("Filtering by callback");
        }
        $newStack = array();
        foreach ($this->elements as $index => $node) {
            $result = phpQuery::callbackRun($callback, array($index, $node));
            if (is_null($result) || (!is_null($result) && $result))
                $newStack[] = $node;
        }
        $this->elements = $newStack;
        return $_skipHistory ? $this : $this->newInstance();
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @link http://docs.jquery.com/Traversing/filter
     */
    public function filter($selectors, $_skipHistory = false) {
        if ($selectors instanceof Callback OR $selectors instanceof Closure)
            return $this->filterCallback($selectors, $_skipHistory);
        if (!$_skipHistory)
            $this->elementsBackup = $this->elements;
        $notSimpleSelector = array(' ', '>', '~', '+', '/');
        if (!is_array($selectors))
            $selectors = $this->parseSelector($selectors);
        if (!$_skipHistory)
            $this->debug(array("Filtering:", $selectors));
        $finalStack = array();
        foreach ($selectors as $selector) {
            $stack = array();
            if (!$selector)
                break;
            // avoid first space or /
            if (in_array($selector[0], $notSimpleSelector))
                $selector = array_slice($selector, 1);
            // PER NODE selector chunks
            foreach ($this->stack() as $node) {
                $break = false;
                foreach ($selector as $s) {
                    if (!($node instanceof DOMELEMENT)) {
                        // all besides DOMElement
                        if ($s[0] == '[') {
                            $attr = trim($s, '[]');
                            if (mb_strpos($attr, '=')) {
                                list( $attr, $val ) = explode('=', $attr);
                                if ($attr == 'nodeType' && $node->nodeType != $val)
                                    $break = true;
                            }
                        } else
                            $break = true;
                    } else {
                        // DOMElement only
                        // ID
                        if ($s[0] == '#') {
                            if ($node->getAttribute('id') != substr($s, 1))
                                $break = true;
                            // CLASSES
                        } else if ($s[0] == '.') {
                            if (!$this->matchClasses($s, $node))
                                $break = true;
                            // ATTRS
                        } else if ($s[0] == '[') {
                            // strip side brackets
                            $attr = trim($s, '[]');
                            if (mb_strpos($attr, '=')) {
                                list($attr, $val) = explode('=', $attr);
                                $val = self::unQuote($val);
                                if ($attr == 'nodeType') {
                                    if ($val != $node->nodeType)
                                        $break = true;
                                } else if ($this->isRegexp($attr)) {
                                    $val = extension_loaded('mbstring') && phpQuery::$mbstringSupport ? quotemeta(trim($val, '"\'')) : preg_quote(trim($val, '"\''), '@');
                                    // switch last character
                                    switch (substr($attr, -1)) {
                                        // quotemeta used insted of preg_quote
                                        // http://code.google.com/p/phpquery/issues/detail?id=76
                                        case '^':
                                            $pattern = '^' . $val;
                                            break;
                                        case '*':
                                            $pattern = '.*' . $val . '.*';
                                            break;
                                        case '$':
                                            $pattern = '.*' . $val . '$';
                                            break;
                                    }
                                    // cut last character
                                    $attr = substr($attr, 0, -1);
                                    $isMatch = extension_loaded('mbstring') && phpQuery::$mbstringSupport ? mb_ereg_match($pattern, $node->getAttribute($attr)) : preg_match("@{$pattern}@", $node->getAttribute($attr));
                                    if (!$isMatch)
                                        $break = true;
                                } else if ($node->getAttribute($attr) != $val)
                                    $break = true;
                            } else if (!$node->hasAttribute($attr))
                                $break = true;
                            // PSEUDO CLASSES
                        } else if ($s[0] == ':') {
                            // skip
                            // TAG
                        } else if (trim($s)) {
                            if ($s != '*') {
                                // TODO namespaces
                                if (isset($node->tagName)) {
                                    if ($node->tagName != $s)
                                        $break = true;
                                } else if ($s == 'html' && !$this->isRoot($node))
                                    $break = true;
                            }
                            // AVOID NON-SIMPLE SELECTORS
                        } else if (in_array($s, $notSimpleSelector)) {
                            $break = true;
                            $this->debug(array('Skipping non simple selector', $selector));
                        }
                    }
                    if ($break)
                        break;
                }
                // if element passed all chunks of selector - add it to new stack
                if (!$break)
                    $stack[] = $node;
            }
            $tmpStack = $this->elements;
            $this->elements = $stack;
            // PER ALL NODES selector chunks
            foreach ($selector as $s)
            // PSEUDO CLASSES
                if ($s[0] == ':')
                    $this->pseudoClasses($s);
            foreach ($this->elements as $node)
            // XXX it should be merged without duplicates
            // but jQuery doesnt do that
                $finalStack[] = $node;
            $this->elements = $tmpStack;
        }
        $this->elements = $finalStack;
        if ($_skipHistory) {
            return $this;
        } else {
            $this->debug("Stack length after filter(): " . count($finalStack));
            return $this->newInstance();
        }
    }

    /**
     *
     * @param $value
     * @return unknown_type
     * @TODO implement in all methods using passed parameters
     */
    protected static function unQuote($value) {
        return $value[0] == '\'' || $value[0] == '"' ? substr($value, 1, -1) : $value;
    }

    /**
     * Enter description here...
     *
     * @link http://docs.jquery.com/Ajax/load
     * @return phpQuery|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @todo Support $selector
     */
    public function load($url, $data = null, $callback = null) {
        if ($data && !is_array($data)) {
            $callback = $data;
            $data = null;
        }
        if (mb_strpos($url, ' ') !== false) {
            $matches = null;
            if (extension_loaded('mbstring') && phpQuery::$mbstringSupport)
                mb_ereg('^([^ ]+) (.*)$', $url, $matches);
            else
                preg_match('^([^ ]+) (.*)$', $url, $matches);
            $url = $matches[1];
            $selector = $matches[2];
            // FIXME this sucks, pass as callback param
            $this->_loadSelector = $selector;
        }
        $ajax = array(
            'url' => $url,
            'type' => $data ? 'POST' : 'GET',
            'data' => $data,
            'complete' => $callback,
            'success' => array($this, '__loadSuccess')
        );
        phpQuery::ajax($ajax);
        return $this;
    }

    /**
     * @access private
     * @param $html
     * @return unknown_type
     */
    public function __loadSuccess($html) {
        if ($this->_loadSelector) {
            $html = phpQuery::newDocument($html)->find($this->_loadSelector);
            unset($this->_loadSelector);
        }
        foreach ($this->stack(1) as $node) {
            phpQuery::pq($node, $this->getDocumentID())
                    ->markup($html);
        }
    }

    /**
     * Enter description here...
     *
     * @return phpQuery|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @todo
     */
    public function css() {
        // TODO
        return $this;
    }

    /**
     * @todo
     *
     */
    public function show() {
        // TODO
        return $this;
    }

    /**
     * @todo
     *
     */
    public function hide() {
        // TODO
        return $this;
    }

    /**
     * Trigger a type of event on every matched element.
     *
     * @param unknown_type $type
     * @param unknown_type $data
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @TODO support more than event in $type (space-separated)
     */
    public function trigger($type, $data = array()) {
        foreach ($this->elements as $node)
            phpQueryEvents::trigger($this->getDocumentID(), $type, $data, $node);
        return $this;
    }

    /**
     * This particular method triggers all bound event handlers on an element (for a specific event type) WITHOUT executing the browsers default actions.
     *
     * @param unknown_type $type
     * @param unknown_type $data
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @TODO
     */
    public function triggerHandler($type, $data = array()) {
        // TODO;
    }

    /**
     * Binds a handler to one or more events (like click) for each matched element.
     * Can also bind custom events.
     *
     * @param unknown_type $type
     * @param unknown_type $data Optional
     * @param unknown_type $callback
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @TODO support '!' (exclusive) events
     * @TODO support more than event in $type (space-separated)
     */
    public function bind($type, $data, $callback = null) {
        // TODO check if $data is callable, not using is_callable
        if (!isset($callback)) {
            $callback = $data;
            $data = null;
        }
        foreach ($this->elements as $node)
            phpQueryEvents::add($this->getDocumentID(), $node, $type, $data, $callback);
        return $this;
    }

    /**
     * Enter description here...
     *
     * @param unknown_type $type
     * @param unknown_type $callback
     * @return unknown
     * @TODO namespace events
     * @TODO support more than event in $type (space-separated)
     */
    public function unbind($type = null, $callback = null) {
        foreach ($this->elements as $node)
            phpQueryEvents::remove($this->getDocumentID(), $node, $type, $callback);
        return $this;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function change($callback = null) {
        if ($callback)
            return $this->bind('change', $callback);
        return $this->trigger('change');
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function submit($callback = null) {
        if ($callback)
            return $this->bind('submit', $callback);
        return $this->trigger('submit');
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function click($callback = null) {
        if ($callback)
            return $this->bind('click', $callback);
        return $this->trigger('click');
    }

    /**
     * Enter description here...
     *
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function wrapAllOld($wrapper) {
        $wrapper = pq($wrapper)->_clone();
        if (!$wrapper->length() || !$this->length())
            return $this;
        $wrapper->insertBefore($this->elements[0]);
        $deepest = $wrapper->elements[0];
        while ($deepest->firstChild && $deepest->firstChild instanceof DOMELEMENT)
            $deepest = $deepest->firstChild;
        pq($deepest)->append($this);
        return $this;
    }

    /**
     * Enter description here...
     *
     * TODO testme...
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function wrapAll($wrapper) {
        if (!$this->length())
            return $this;
        return phpQuery::pq($wrapper, $this->getDocumentID())
                        ->clone()
                        ->insertBefore($this->get(0))
                        ->map(array($this, '___wrapAllCallback'))
                        ->append($this);
    }

    /**
     *
     * @param $node
     * @return unknown_type
     * @access private
     */
    public function ___wrapAllCallback($node) {
        $deepest = $node;
        while ($deepest->firstChild && $deepest->firstChild instanceof DOMELEMENT)
            $deepest = $deepest->firstChild;
        return $deepest;
    }

    /**
     * Enter description here...
     * NON JQUERY METHOD
     *
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function wrapAllPHP($codeBefore, $codeAfter) {
        return $this
                        ->slice(0, 1)
                        ->beforePHP($codeBefore)
                        ->end()
                        ->slice(-1)
                        ->afterPHP($codeAfter)
                        ->end();
    }

    /**
     * Enter description here...
     *
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function wrap($wrapper) {
        foreach ($this->stack() as $node)
            phpQuery::pq($node, $this->getDocumentID())->wrapAll($wrapper);
        return $this;
    }

    /**
     * Enter description here...
     *
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function wrapPHP($codeBefore, $codeAfter) {
        foreach ($this->stack() as $node)
            phpQuery::pq($node, $this->getDocumentID())->wrapAllPHP($codeBefore, $codeAfter);
        return $this;
    }

    /**
     * Enter description here...
     *
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function wrapInner($wrapper) {
        foreach ($this->stack() as $node)
            phpQuery::pq($node, $this->getDocumentID())->contents()->wrapAll($wrapper);
        return $this;
    }

    /**
     * Enter description here...
     *
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function wrapInnerPHP($codeBefore, $codeAfter) {
        foreach ($this->stack(1) as $node)
            phpQuery::pq($node, $this->getDocumentID())->contents()
                    ->wrapAllPHP($codeBefore, $codeAfter);
        return $this;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @testme Support for text nodes
     */
    public function contents() {
        $stack = array();
        foreach ($this->stack(1) as $el) {
            // FIXME (fixed) http://code.google.com/p/phpquery/issues/detail?id=56
//			if (! isset($el->childNodes))
//				continue;
            foreach ($el->childNodes as $node) {
                $stack[] = $node;
            }
        }
        return $this->newInstance($stack);
    }

    /**
     * Enter description here...
     *
     * jQuery difference.
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function contentsUnwrap() {
        foreach ($this->stack(1) as $node) {
            if (!$node->parentNode)
                continue;
            $childNodes = array();
            // any modification in DOM tree breaks childNodes iteration, so cache them first
            foreach ($node->childNodes as $chNode)
                $childNodes[] = $chNode;
            foreach ($childNodes as $chNode)
//				$node->parentNode->appendChild($chNode);
                $node->parentNode->insertBefore($chNode, $node);
            $node->parentNode->removeChild($node);
        }
        return $this;
    }

    /**
     * Enter description here...
     *
     * jQuery difference.
     */
    public function switchWith($markup) {
        $markup = pq($markup, $this->getDocumentID());
        $content = null;
        foreach ($this->stack(1) as $node) {
            pq($node)
                    ->contents()->toReference($content)->end()
                    ->replaceWith($markup->clone()->append($content));
        }
        return $this;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function eq($num) {
        $oldStack = $this->elements;
        $this->elementsBackup = $this->elements;
        $this->elements = array();
        if (isset($oldStack[$num]))
            $this->elements[] = $oldStack[$num];
        return $this->newInstance();
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function size() {
        return count($this->elements);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @deprecated Use length as attribute
     */
    public function length() {
        return $this->size();
    }

    public function count() {
        return $this->size();
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @todo $level
     */
    public function end($level = 1) {
//		$this->elements = array_pop( $this->history );
//		return $this;
//		$this->previous->DOM = $this->DOM;
//		$this->previous->XPath = $this->XPath;
        return $this->previous ? $this->previous : $this;
    }

    /**
     * Enter description here...
     * Normal use ->clone() .
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @access private
     */
    public function _clone() {
        $newStack = array();
        //pr(array('copy... ', $this->whois()));
        //$this->dumpHistory('copy');
        $this->elementsBackup = $this->elements;
        foreach ($this->elements as $node) {
            $newStack[] = $node->cloneNode(true);
        }
        $this->elements = $newStack;
        return $this->newInstance();
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function replaceWithPHP($code) {
        return $this->replaceWith(phpQuery::php($code));
    }

    /**
     * Enter description here...
     *
     * @param String|phpQuery $content
     * @link http://docs.jquery.com/Manipulation/replaceWith#content
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function replaceWith($content) {
        return $this->after($content)->remove();
    }

    /**
     * Enter description here...
     *
     * @param String $selector
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @todo this works ?
     */
    public function replaceAll($selector) {
        foreach (phpQuery::pq($selector, $this->getDocumentID()) as $node)
            phpQuery::pq($node, $this->getDocumentID())
                    ->after($this->_clone())
                    ->remove();
        return $this;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function remove($selector = null) {
        $loop = $selector ? $this->filter($selector)->elements : $this->elements;
        foreach ($loop as $node) {
            if (!$node->parentNode)
                continue;
            if (isset($node->tagName))
                $this->debug("Removing '{$node->tagName}'");
            $node->parentNode->removeChild($node);
            // Mutation event
            $event = new DOMEvent(array(
                'target' => $node,
                'type' => 'DOMNodeRemoved'
            ));
            phpQueryEvents::trigger($this->getDocumentID(), $event->type, array($event), $node
            );
        }
        return $this;
    }

    protected function markupEvents($newMarkup, $oldMarkup, $node) {
        if ($node->tagName == 'textarea' && $newMarkup != $oldMarkup) {
            $event = new DOMEvent(array(
                'target' => $node,
                'type' => 'change'
            ));
            phpQueryEvents::trigger($this->getDocumentID(), $event->type, array($event), $node
            );
        }
    }

    /**
     * jQuey difference
     *
     * @param $markup
     * @return unknown_type
     * @TODO trigger change event for textarea
     */
    public function markup($markup = null, $callback1 = null, $callback2 = null, $callback3 = null) {
        $args = func_get_args();
        if ($this->documentWrapper->isXML)
            return call_user_func_array(array($this, 'xml'), $args);
        else
            return call_user_func_array(array($this, 'html'), $args);
    }

    /**
     * jQuey difference
     *
     * @param $markup
     * @return unknown_type
     */
    public function markupOuter($callback1 = null, $callback2 = null, $callback3 = null) {
        $args = func_get_args();
        if ($this->documentWrapper->isXML)
            return call_user_func_array(array($this, 'xmlOuter'), $args);
        else
            return call_user_func_array(array($this, 'htmlOuter'), $args);
    }

    /**
     * Enter description here...
     *
     * @param unknown_type $html
     * @return string|phpQuery|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @TODO force html result
     */
    public function html($html = null, $callback1 = null, $callback2 = null, $callback3 = null) {
        if (isset($html)) {
            // INSERT
            $nodes = $this->documentWrapper->import($html);
            $this->empty();
            foreach ($this->stack(1) as $alreadyAdded => $node) {
                // for now, limit events for textarea
                if (($this->isXHTML() || $this->isHTML()) && $node->tagName == 'textarea')
                    $oldHtml = pq($node, $this->getDocumentID())->markup();
                foreach ($nodes as $newNode) {
                    $node->appendChild($alreadyAdded ? $newNode->cloneNode(true) : $newNode
                    );
                }
                // for now, limit events for textarea
                if (($this->isXHTML() || $this->isHTML()) && $node->tagName == 'textarea')
                    $this->markupEvents($html, $oldHtml, $node);
            }
            return $this;
        } else {
            // FETCH
            $return = $this->documentWrapper->markup($this->elements, true);
            $args = func_get_args();
            foreach (array_slice($args, 1) as $callback) {
                $return = phpQuery::callbackRun($callback, array($return));
            }
            return $return;
        }
    }

    /**
     * @TODO force xml result
     */
    public function xml($xml = null, $callback1 = null, $callback2 = null, $callback3 = null) {
        $args = func_get_args();
        return call_user_func_array(array($this, 'html'), $args);
    }

    /**
     * Enter description here...
     * @TODO force html result
     *
     * @return String
     */
    public function htmlOuter($callback1 = null, $callback2 = null, $callback3 = null) {
        $markup = $this->documentWrapper->markup($this->elements);
        // pass thou callbacks
        $args = func_get_args();
        foreach ($args as $callback) {
            $markup = phpQuery::callbackRun($callback, array($markup));
        }
        return $markup;
    }

    /**
     * @TODO force xml result
     */
    public function xmlOuter($callback1 = null, $callback2 = null, $callback3 = null) {
        $args = func_get_args();
        return call_user_func_array(array($this, 'htmlOuter'), $args);
    }

    public function __toString() {
        return $this->markupOuter();
    }

    /**
     * Just like html(), but returns markup with VALID (dangerous) PHP tags.
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @todo support returning markup with PHP tags when called without param
     */
    public function php($code = null) {
        return $this->markupPHP($code);
    }

    /**
     * Enter description here...
     * 
     * @param $code
     * @return unknown_type
     */
    public function markupPHP($code = null) {
        return isset($code) ? $this->markup(phpQuery::php($code)) : phpQuery::markupToPHP($this->markup());
    }

    /**
     * Enter description here...
     * 
     * @param $code
     * @return unknown_type
     */
    public function markupOuterPHP() {
        return phpQuery::markupToPHP($this->markupOuter());
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function children($selector = null) {
        $stack = array();
        foreach ($this->stack(1) as $node) {
//			foreach($node->getElementsByTagName('*') as $newNode) {
            foreach ($node->childNodes as $newNode) {
                if ($newNode->nodeType != 1)
                    continue;
                if ($selector && !$this->is($selector, $newNode))
                    continue;
                if ($this->elementsContainsNode($newNode, $stack))
                    continue;
                $stack[] = $newNode;
            }
        }
        $this->elementsBackup = $this->elements;
        $this->elements = $stack;
        return $this->newInstance();
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function ancestors($selector = null) {
        return $this->children($selector);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function append($content) {
        return $this->insert($content, __FUNCTION__);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function appendPHP($content) {
        return $this->insert("<php><!-- {$content} --></php>", 'append');
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function appendTo($seletor) {
        return $this->insert($seletor, __FUNCTION__);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function prepend($content) {
        return $this->insert($content, __FUNCTION__);
    }

    /**
     * Enter description here...
     *
     * @todo accept many arguments, which are joined, arrays maybe also
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function prependPHP($content) {
        return $this->insert("<php><!-- {$content} --></php>", 'prepend');
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function prependTo($seletor) {
        return $this->insert($seletor, __FUNCTION__);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function before($content) {
        return $this->insert($content, __FUNCTION__);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function beforePHP($content) {
        return $this->insert("<php><!-- {$content} --></php>", 'before');
    }

    /**
     * Enter description here...
     *
     * @param String|phpQuery
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function insertBefore($seletor) {
        return $this->insert($seletor, __FUNCTION__);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function after($content) {
        return $this->insert($content, __FUNCTION__);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function afterPHP($content) {
        return $this->insert("<php><!-- {$content} --></php>", 'after');
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function insertAfter($seletor) {
        return $this->insert($seletor, __FUNCTION__);
    }

    /**
     * Internal insert method. Don't use it.
     *
     * @param unknown_type $target
     * @param unknown_type $type
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @access private
     */
    public function insert($target, $type) {
        $this->debug("Inserting data with '{$type}'");
        $to = false;
        switch ($type) {
            case 'appendTo':
            case 'prependTo':
            case 'insertBefore':
            case 'insertAfter':
                $to = true;
        }
        switch (gettype($target)) {
            case 'string':
                $insertFrom = $insertTo = array();
                if ($to) {
                    // INSERT TO
                    $insertFrom = $this->elements;
                    if (phpQuery::isMarkup($target)) {
                        // $target is new markup, import it
                        $insertTo = $this->documentWrapper->import($target);
                        // insert into selected element
                    } else {
                        // $tagret is a selector
                        $thisStack = $this->elements;
                        $this->toRoot();
                        $insertTo = $this->find($target)->elements;
                        $this->elements = $thisStack;
                    }
                } else {
                    // INSERT FROM
                    $insertTo = $this->elements;
                    $insertFrom = $this->documentWrapper->import($target);
                }
                break;
            case 'object':
                $insertFrom = $insertTo = array();
                // phpQuery
                if ($target instanceof self) {
                    if ($to) {
                        $insertTo = $target->elements;
                        if ($this->documentFragment && $this->stackIsRoot())
                        // get all body children
//							$loop = $this->find('body > *')->elements;
                        // TODO test it, test it hard...
//							$loop = $this->newInstance($this->root)->find('> *')->elements;
                            $loop = $this->root->childNodes;
                        else
                            $loop = $this->elements;
                        // import nodes if needed
                        $insertFrom = $this->getDocumentID() == $target->getDocumentID() ? $loop : $target->documentWrapper->import($loop);
                    } else {
                        $insertTo = $this->elements;
                        if ($target->documentFragment && $target->stackIsRoot())
                        // get all body children
//							$loop = $target->find('body > *')->elements;
                            $loop = $target->root->childNodes;
                        else
                            $loop = $target->elements;
                        // import nodes if needed
                        $insertFrom = $this->getDocumentID() == $target->getDocumentID() ? $loop : $this->documentWrapper->import($loop);
                    }
                    // DOMNODE
                } elseif ($target instanceof DOMNODE) {
                    // import node if needed
//					if ( $target->ownerDocument != $this->DOM )
//						$target = $this->DOM->importNode($target, true);
                    if ($to) {
                        $insertTo = array($target);
                        if ($this->documentFragment && $this->stackIsRoot())
                        // get all body children
                            $loop = $this->root->childNodes;
//							$loop = $this->find('body > *')->elements;
                        else
                            $loop = $this->elements;
                        foreach ($loop as $fromNode)
                        // import nodes if needed
                            $insertFrom[] = !$fromNode->ownerDocument->isSameNode($target->ownerDocument) ? $target->ownerDocument->importNode($fromNode, true) : $fromNode;
                    } else {
                        // import node if needed
                        if (!$target->ownerDocument->isSameNode($this->document))
                            $target = $this->document->importNode($target, true);
                        $insertTo = $this->elements;
                        $insertFrom[] = $target;
                    }
                }
                break;
        }
        phpQuery::debug("From " . count($insertFrom) . "; To " . count($insertTo) . " nodes");
        foreach ($insertTo as $insertNumber => $toNode) {
            // we need static relative elements in some cases
            switch ($type) {
                case 'prependTo':
                case 'prepend':
                    $firstChild = $toNode->firstChild;
                    break;
                case 'insertAfter':
                case 'after':
                    $nextSibling = $toNode->nextSibling;
                    break;
            }
            foreach ($insertFrom as $fromNode) {
                // clone if inserted already before
                $insert = $insertNumber ? $fromNode->cloneNode(true) : $fromNode;
                switch ($type) {
                    case 'appendTo':
                    case 'append':
//						$toNode->insertBefore(
//							$fromNode,
//							$toNode->lastChild->nextSibling
//						);
                        $toNode->appendChild($insert);
                        $eventTarget = $insert;
                        break;
                    case 'prependTo':
                    case 'prepend':
                        $toNode->insertBefore(
                                $insert, $firstChild
                        );
                        break;
                    case 'insertBefore':
                    case 'before':
                        if (!$toNode->parentNode)
                            throw new Exception("No parentNode, can't do {$type}()");
                        else
                            $toNode->parentNode->insertBefore(
                                    $insert, $toNode
                            );
                        break;
                    case 'insertAfter':
                    case 'after':
                        if (!$toNode->parentNode)
                            throw new Exception("No parentNode, can't do {$type}()");
                        else
                            $toNode->parentNode->insertBefore(
                                    $insert, $nextSibling
                            );
                        break;
                }
                // Mutation event
                $event = new DOMEvent(array(
                    'target' => $insert,
                    'type' => 'DOMNodeInserted'
                ));
                phpQueryEvents::trigger($this->getDocumentID(), $event->type, array($event), $insert
                );
            }
        }
        return $this;
    }

    /**
     * Enter description here...
     *
     * @return Int
     */
    public function index($subject) {
        $index = -1;
        $subject = $subject instanceof phpQueryObject ? $subject->elements[0] : $subject;
        foreach ($this->newInstance() as $k => $node) {
            if ($node->isSameNode($subject))
                $index = $k;
        }
        return $index;
    }

    /**
     * Enter description here...
     *
     * @param unknown_type $start
     * @param unknown_type $end
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @testme
     */
    public function slice($start, $end = null) {
//		$last = count($this->elements)-1;
//		$end = $end
//			? min($end, $last)
//			: $last;
//		if ($start < 0)
//			$start = $last+$start;
//		if ($start > $last)
//			return array();
        if ($end > 0)
            $end = $end - $start;
        return $this->newInstance(
                        array_slice($this->elements, $start, $end)
        );
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function reverse() {
        $this->elementsBackup = $this->elements;
        $this->elements = array_reverse($this->elements);
        return $this->newInstance();
    }

    /**
     * Return joined text content.
     * @return String
     */
    public function text($text = null, $callback1 = null, $callback2 = null, $callback3 = null) {
        if (isset($text))
            return $this->html(htmlspecialchars($text));
        $args = func_get_args();
        $args = array_slice($args, 1);
        $return = '';
        foreach ($this->elements as $node) {
            $text = $node->textContent;
            if (count($this->elements) > 1 && $text)
                $text .= "\n";
            foreach ($args as $callback) {
                $text = phpQuery::callbackRun($callback, array($text));
            }
            $return .= $text;
        }
        return $return;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function plugin($class, $file = null) {
        phpQuery::plugin($class, $file);
        return $this;
    }

    /**
     * Deprecated, use $pq->plugin() instead.
     *
     * @deprecated
     * @param $class
     * @param $file
     * @return unknown_type
     */
    public static function extend($class, $file = null) {
        return $this->plugin($class, $file);
    }

    /**
     *
     * @access private
     * @param $method
     * @param $args
     * @return unknown_type
     */
    public function __call($method, $args) {
        $aliasMethods = array('clone', 'empty');
        if (isset(phpQuery::$extendMethods[$method])) {
            array_unshift($args, $this);
            return phpQuery::callbackRun(
                            phpQuery::$extendMethods[$method], $args
            );
        } else if (isset(phpQuery::$pluginsMethods[$method])) {
            array_unshift($args, $this);
            $class = phpQuery::$pluginsMethods[$method];
            $realClass = "phpQueryObjectPlugin_$class";
            $return = call_user_func_array(
                    array($realClass, $method), $args
            );
            // XXX deprecate ?
            return is_null($return) ? $this : $return;
        } else if (in_array($method, $aliasMethods)) {
            return call_user_func_array(array($this, '_' . $method), $args);
        } else
            throw new Exception("Method '{$method}' doesnt exist");
    }

    /**
     * Safe rename of next().
     *
     * Use it ONLY when need to call next() on an iterated object (in same time).
     * Normaly there is no need to do such thing ;)
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @access private
     */
    public function _next($selector = null) {
        return $this->newInstance(
                        $this->getElementSiblings('nextSibling', $selector, true)
        );
    }

    /**
     * Use prev() and next().
     *
     * @deprecated
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @access private
     */
    public function _prev($selector = null) {
        return $this->prev($selector);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function prev($selector = null) {
        return $this->newInstance(
                        $this->getElementSiblings('previousSibling', $selector, true)
        );
    }

    /**
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @todo
     */
    public function prevAll($selector = null) {
        return $this->newInstance(
                        $this->getElementSiblings('previousSibling', $selector)
        );
    }

    /**
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     * @todo FIXME: returns source elements insted of next siblings
     */
    public function nextAll($selector = null) {
        return $this->newInstance(
                        $this->getElementSiblings('nextSibling', $selector)
        );
    }

    /**
     * @access private
     */
    protected function getElementSiblings($direction, $selector = null, $limitToOne = false) {
        $stack = array();
        $count = 0;
        foreach ($this->stack() as $node) {
            $test = $node;
            while (isset($test->{$direction}) && $test->{$direction}) {
                $test = $test->{$direction};
                if (!$test instanceof DOMELEMENT)
                    continue;
                $stack[] = $test;
                if ($limitToOne)
                    break;
            }
        }
        if ($selector) {
            $stackOld = $this->elements;
            $this->elements = $stack;
            $stack = $this->filter($selector, true)->stack();
            $this->elements = $stackOld;
        }
        return $stack;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function siblings($selector = null) {
        $stack = array();
        $siblings = array_merge(
                $this->getElementSiblings('previousSibling', $selector), $this->getElementSiblings('nextSibling', $selector)
        );
        foreach ($siblings as $node) {
            if (!$this->elementsContainsNode($node, $stack))
                $stack[] = $node;
        }
        return $this->newInstance($stack);
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function not($selector = null) {
        if (is_string($selector))
            phpQuery::debug(array('not', $selector));
        else
            phpQuery::debug('not');
        $stack = array();
        if ($selector instanceof self || $selector instanceof DOMNODE) {
            foreach ($this->stack() as $node) {
                if ($selector instanceof self) {
                    $matchFound = false;
                    foreach ($selector->stack() as $notNode) {
                        if ($notNode->isSameNode($node))
                            $matchFound = true;
                    }
                    if (!$matchFound)
                        $stack[] = $node;
                } else if ($selector instanceof DOMNODE) {
                    if (!$selector->isSameNode($node))
                        $stack[] = $node;
                } else {
                    if (!$this->is($selector))
                        $stack[] = $node;
                }
            }
        } else {
            $orgStack = $this->stack();
            $matched = $this->filter($selector, true)->stack();
//			$matched = array();
//			// simulate OR in filter() instead of AND 5y
//			foreach($this->parseSelector($selector) as $s) {
//				$matched = array_merge($matched,
//					$this->filter(array($s))->stack()
//				);
//			}
            foreach ($orgStack as $node)
                if (!$this->elementsContainsNode($node, $matched))
                    $stack[] = $node;
        }
        return $this->newInstance($stack);
    }

    /**
     * Enter description here...
     *
     * @param string|phpQueryObject
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function add($selector = null) {
        if (!$selector)
            return $this;
        $stack = array();
        $this->elementsBackup = $this->elements;
        $found = phpQuery::pq($selector, $this->getDocumentID());
        $this->merge($found->elements);
        return $this->newInstance();
    }

    /**
     * @access private
     */
    protected function merge() {
        foreach (func_get_args() as $nodes)
            foreach ($nodes as $newNode)
                if (!$this->elementsContainsNode($newNode))
                    $this->elements[] = $newNode;
    }

    /**
     * @access private
     * TODO refactor to stackContainsNode
     */
    protected function elementsContainsNode($nodeToCheck, $elementsStack = null) {
        $loop = !is_null($elementsStack) ? $elementsStack : $this->elements;
        foreach ($loop as $node) {
            if ($node->isSameNode($nodeToCheck))
                return true;
        }
        return false;
    }

    /**
     * Enter description here...
     *
     * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
     */
    public function parent($selector = null) {
    $stack = array();
    foreach($this->elements as $node)
             if(
        $node->parentNode &&!$this->elementsContainsNode($node->parentNode, $stack))
            $
            stack[]   = $node->parentNode;
    $this->elementsBackup = $this->elements;
    $this->elements = $stack;
    if ($selector)
        $this->filter($selector, true);
    return $this->newInstance();
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function parents($selector = null) {
    $stack = array();
    if (!$this->elements)
        $this->debug('parents() - stack empty');
    foreach ($this->elements as $node) {
        $test = $node;
        while ($test->parentNode) {
            $test = $test->parentNode;
            if ($this->isRoot($test))
                break;
            if (!$this->elementsContainsNode($test, $stack)) {
                $stack[] = $test;
                continue;
            }
        }
    }
    $this->elementsBackup = $this->elements;
    $this->elements = $stack;
    if ($selector)
        $this->filter($selector, true);
    return $this->newInstance();
}

/**
 * Internal stack iterator.
 *
 * @access private
 */
public function stack($nodeTypes = null) {
    if (!isset($nodeTypes))
        return $this->elements;
    if (!is_array($nodeTypes))
        $nodeTypes = array($nodeTypes);
    $return = array();
    foreach ($this->elements as $node) {
        if (in_array($node->nodeType, $nodeTypes))
            $return[] = $node;
    }
    return $return;
}

// TODO phpdoc; $oldAttr is result of hasAttribute, before any changes
protected function attrEvents($attr, $oldAttr, $oldValue, $node) {
    // skip events for XML documents
    if (!$this->isXHTML() && !$this->isHTML())
        return;
    $event = null;
    // identify
    $isInputValue = $node->tagName == 'input' && (
            in_array($node->getAttribute('type'), array('text', 'password', 'hidden')) || !$node->getAttribute('type')
            );
    $isRadio = $node->tagName == 'input' && $node->getAttribute('type') == 'radio';
    $isCheckbox = $node->tagName == 'input' && $node->getAttribute('type') == 'checkbox';
    $isOption = $node->tagName == 'option';
    if ($isInputValue && $attr == 'value' && $oldValue != $node->getAttribute($attr)) {
        $event = new DOMEvent(array(
            'target' => $node,
            'type' => 'change'
        ));
    } else if (($isRadio || $isCheckbox) && $attr == 'checked' && (
            // check
            (!$oldAttr && $node->hasAttribute($attr))
            // un-check
            || (!$node->hasAttribute($attr) && $oldAttr)
            )) {
        $event = new DOMEvent(array(
            'target' => $node,
            'type' => 'change'
        ));
    } else if ($isOption && $node->parentNode && $attr == 'selected' && (
            // select
            (!$oldAttr && $node->hasAttribute($attr))
            // un-select
            || (!$node->hasAttribute($attr) && $oldAttr)
            )) {
        $event = new DOMEvent(array(
            'target' => $node->parentNode,
            'type' => 'change'
        ));
    }
    if ($event) {
        phpQueryEvents::trigger($this->getDocumentID(), $event->type, array($event), $node
        );
    }
}

public function attr($attr = null, $value = null) {
    foreach ($this->stack(1) as $node) {
        if (!is_null($value)) {
            $loop = $attr == '*' ? $this->getNodeAttrs($node) : array($attr);
            foreach ($loop as $a) {
                $oldValue = $node->getAttribute($a);
                $oldAttr = $node->hasAttribute($a);
                // TODO raises an error when charset other than UTF-8
                // while document's charset is also not UTF-8
                @$node->setAttribute($a, $value);
                $this->attrEvents($a, $oldAttr, $oldValue, $node);
            }
        } else if ($attr == '*') {
            // jQuery difference
            $return = array();
            foreach ($node->attributes as $n => $v)
                $return[$n] = $v->value;
            return $return;
        } else
            return $node->hasAttribute($attr) ? $node->getAttribute($attr) : null;
    }
    return is_null($value) ? '' : $this;
}

/**
 * @access private
 */
protected function getNodeAttrs($node) {
    $return = array();
    foreach ($node->attributes as $n => $o)
        $return[] = $n;
    return $return;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 * @todo check CDATA ???
 */
public function attrPHP($attr, $code) {
    if (!is_null($code)) {
        $value = '<' . '?php ' . $code . ' ?' . '>';
        // TODO tempolary solution
        // http://code.google.com/p/phpquery/issues/detail?id=17
//			if (function_exists('mb_detect_encoding') && mb_detect_encoding($value) == 'ASCII')
//				$value	= mb_convert_encoding($value, 'UTF-8', 'HTML-ENTITIES');
    }
    foreach ($this->stack(1) as $node) {
        if (!is_null($code)) {
//				$attrNode = $this->DOM->createAttribute($attr);
            $node->setAttribute($attr, $value);
//				$attrNode->value = $value;
//				$node->appendChild($attrNode);
        } else if ($attr == '*') {
            // jQuery diff
            $return = array();
            foreach ($node->attributes as $n => $v)
                $return[$n] = $v->value;
            return $return;
        } else
            return $node->getAttribute($attr);
    }
    return $this;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function removeAttr($attr) {
    foreach ($this->stack(1) as $node) {
        $loop = $attr == '*' ? $this->getNodeAttrs($node) : array($attr);
        foreach ($loop as $a) {
            $oldValue = $node->getAttribute($a);
            $node->removeAttribute($a);
            $this->attrEvents($a, $oldValue, null, $node);
        }
    }
    return $this;
}

/**
 * Return form element value.
 *
 * @return String Fields value.
 */
public function val($val = null) {
    if (!isset($val)) {
        if ($this->eq(0)->is('select')) {
            $selected = $this->eq(0)->find('option[selected=selected]');
            if ($selected->is('[value]'))
                return $selected->attr('value');
            else
                return $selected->text();
        } else if ($this->eq(0)->is('textarea'))
            return $this->eq(0)->markup();
        else
            return $this->eq(0)->attr('value');
    } else {
        $_val = null;
        foreach ($this->stack(1) as $node) {
            $node = pq($node, $this->getDocumentID());
            if (is_array($val) && in_array($node->attr('type'), array('checkbox', 'radio'))) {
                $isChecked = in_array($node->attr('value'), $val) || in_array($node->attr('name'), $val);
                if ($isChecked)
                    $node->attr('checked', 'checked');
                else
                    $node->removeAttr('checked');
            } else if ($node->get(0)->tagName == 'select') {
                if (!isset($_val)) {
                    $_val = array();
                    if (!is_array($val))
                        $_val = array((string) $val);
                    else
                        foreach ($val as $v)
                            $_val[] = $v;
                }
                foreach ($node['option']->stack(1) as $option) {
                    $option = pq($option, $this->getDocumentID());
                    $selected = false;
                    // XXX: workaround for string comparsion, see issue #96
                    // http://code.google.com/p/phpquery/issues/detail?id=96
                    $selected = is_null($option->attr('value')) ? in_array($option->markup(), $_val) : in_array($option->attr('value'), $_val);
//						$optionValue = $option->attr('value');
//						$optionText = $option->text();
//						$optionTextLenght = mb_strlen($optionText);
//						foreach($_val as $v)
//							if ($optionValue == $v)
//								$selected = true;
//							else if ($optionText == $v && $optionTextLenght == mb_strlen($v))
//								$selected = true;
                    if ($selected)
                        $option->attr('selected', 'selected');
                    else
                        $option->removeAttr('selected');
                }
            } else if ($node->get(0)->tagName == 'textarea')
                $node->markup($val);
            else
                $node->attr('value', $val);
        }
    }
    return $this;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function andSelf() {
    if ($this->previous)
        $this->elements = array_merge($this->elements, $this->previous->elements);
    return $this;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function addClass($className) {
    if (!$className)
        return $this;
    foreach ($this->stack(1) as $node) {
        if (!$this->is(".$className", $node))
            $node->setAttribute(
                    'class', trim($node->getAttribute('class') . ' ' . $className)
            );
    }
    return $this;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function addClassPHP($className) {
    foreach ($this->stack(1) as $node) {
        $classes = $node->getAttribute('class');
        $newValue = $classes ? $classes . ' <' . '?php ' . $className . ' ?' . '>' : '<' . '?php ' . $className . ' ?' . '>';
        $node->setAttribute('class', $newValue);
    }
    return $this;
}

/**
 * Enter description here...
 *
 * @param	string	$className
 * @return	bool
 */
public function hasClass($className) {
    foreach ($this->stack(1) as $node) {
        if ($this->is(".$className", $node))
            return true;
    }
    return false;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function removeClass($className) {
    foreach ($this->stack(1) as $node) {
        $classes = explode(' ', $node->getAttribute('class'));
        if (in_array($className, $classes)) {
            $classes = array_diff($classes, array($className));
            if ($classes)
                $node->setAttribute('class', implode(' ', $classes));
            else
                $node->removeAttribute('class');
        }
    }
    return $this;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function toggleClass($className) {
    foreach ($this->stack(1) as $node) {
        if ($this->is($node, '.' . $className))
            $this->removeClass($className);
        else
            $this->addClass($className);
    }
    return $this;
}

/**
 * Proper name without underscore (just ->empty()) also works.
 *
 * Removes all child nodes from the set of matched elements.
 *
 * Example:
 * pq("p")._empty()
 *
 * HTML:
 * <p>Hello, <span>Person</span> <a href="#">and person</a></p>
 *
 * Result:
 * [ <p></p> ]
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 * @access private
 */
public function _empty() {
    foreach ($this->stack(1) as $node) {
        // thx to 'dave at dgx dot cz'
        $node->nodeValue = '';
    }
    return $this;
}

/**
 * Enter description here...
 *
 * @param array|string $callback Expects $node as first param, $index as second
 * @param array $scope External variables passed to callback. Use compact('varName1', 'varName2'...) and extract($scope)
 * @param array $arg1 Will ba passed as third and futher args to callback.
 * @param array $arg2 Will ba passed as fourth and futher args to callback, and so on...
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function each($callback, $param1 = null, $param2 = null, $param3 = null) {
    $paramStructure = null;
    if (func_num_args() > 1) {
        $paramStructure = func_get_args();
        $paramStructure = array_slice($paramStructure, 1);
    }
    foreach ($this->elements as $v)
        phpQuery::callbackRun($callback, array($v), $paramStructure);
    return $this;
}

/**
 * Run callback on actual object.
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function callback($callback, $param1 = null, $param2 = null, $param3 = null) {
    $params = func_get_args();
    $params[0] = $this;
    phpQuery::callbackRun($callback, $params);
    return $this;
}

/**
 * Enter description here...
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 * @todo add $scope and $args as in each() ???
 */
public function map($callback, $param1 = null, $param2 = null, $param3 = null) {
//		$stack = array();
////		foreach($this->newInstance() as $node) {
//		foreach($this->newInstance() as $node) {
//			$result = call_user_func($callback, $node);
//			if ($result)
//				$stack[] = $result;
//		}
    $params = func_get_args();
    array_unshift($params, $this->elements);
    return $this->newInstance(
                    call_user_func_array(array('phpQuery', 'map'), $params)
//			phpQuery::map($this->elements, $callback)
    );
}

/**
 * Enter description here...
 * 
 * @param <type> $key
 * @param <type> $value
 */
public function data($key, $value = null) {
    if (!isset($value)) {
        // TODO? implement specific jQuery behavior od returning parent values
        // is child which we look up doesn't exist
        return phpQuery::data($this->get(0), $key, $value, $this->getDocumentID());
    } else {
        foreach ($this as $node)
            phpQuery::data($node, $key, $value, $this->getDocumentID());
        return $this;
    }
}

/**
 * Enter description here...
 * 
 * @param <type> $key
 */
public function removeData($key) {
    foreach ($this as $node)
        phpQuery::removeData($node, $key, $this->getDocumentID());
    return $this;
}

// INTERFACE IMPLEMENTATIONS
// ITERATOR INTERFACE
/**
 * @access private
 */
public function rewind() {
    $this->debug('iterating foreach');
//		phpQuery::selectDocument($this->getDocumentID());
    $this->elementsBackup = $this->elements;
    $this->elementsInterator = $this->elements;
    $this->valid = isset($this->elements[0]) ? 1 : 0;
// 		$this->elements = $this->valid
// 			? array($this->elements[0])
// 			: array();
    $this->current = 0;
}

/**
 * @access private
 */
public function current() {
    return $this->elementsInterator[$this->current];
}

/**
 * @access private
 */
public function key() {
    return $this->current;
}

/**
 * Double-function method.
 *
 * First: main iterator interface method.
 * Second: Returning next sibling, alias for _next().
 *
 * Proper functionality is choosed automagicaly.
 *
 * @see phpQueryObject::_next()
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 */
public function next($cssSelector = null) {
//		if ($cssSelector || $this->valid)
//			return $this->_next($cssSelector);
    $this->valid = isset($this->elementsInterator[$this->current + 1]) ? true : false;
    if (!$this->valid && $this->elementsInterator) {
        $this->elementsInterator = null;
    } else if ($this->valid) {
        $this->current++;
    } else {
        return $this->_next($cssSelector);
    }
}

/**
 * @access private
 */
public function valid() {
    return $this->valid;
}

// ITERATOR INTERFACE END
// ARRAYACCESS INTERFACE
/**
 * @access private
 */
public function offsetExists($offset) {
    return $this->find($offset)->size() > 0;
}

/**
 * @access private
 */
public function offsetGet($offset) {
    return $this->find($offset);
}

/**
 * @access private
 */
public function offsetSet($offset, $value) {
//		$this->find($offset)->replaceWith($value);
    $this->find($offset)->html($value);
}

/**
 * @access private
 */
public function offsetUnset($offset) {
    // empty
    throw new Exception("Can't do unset, use array interface only for calling queries and replacing HTML.");
}

// ARRAYACCESS INTERFACE END
/**
 * Returns node's XPath.
 *
 * @param unknown_type $oneNode
 * @return string
 * @TODO use native getNodePath is avaible
 * @access private
 */
protected function getNodeXpath($oneNode = null, $namespace = null) {
    $return = array();
    $loop = $oneNode ? array($oneNode) : $this->elements;
//		if ($namespace)
//			$namespace .= ':';
    foreach ($loop as $node) {
        if ($node instanceof DOMDOCUMENT) {
            $return[] = '';
            continue;
        }
        $xpath = array();
        while (!($node instanceof DOMDOCUMENT)) {
            $i = 1;
            $sibling = $node;
            while ($sibling->previousSibling) {
                $sibling = $sibling->previousSibling;
                $isElement = $sibling instanceof DOMELEMENT;
                if ($isElement && $sibling->tagName == $node->tagName)
                    $i++;
            }
            $xpath[] = $this->isXML() ? "*[local-name()='{$node->tagName}'][{$i}]" : "{$node->tagName}[{$i}]";
            $node = $node->parentNode;
        }
        $xpath = join('/', array_reverse($xpath));
        $return[] = '/' . $xpath;
    }
    return $oneNode ? $return[0] : $return;
}

// HELPERS
public function whois($oneNode = null) {
    $return = array();
    $loop = $oneNode ? array($oneNode) : $this->elements;
    foreach ($loop as $node) {
        if (isset($node->tagName)) {
            $tag = in_array($node->tagName, array('php', 'js')) ? strtoupper($node->tagName) : $node->tagName;
            $return[] = $tag
                    . ($node->getAttribute('id') ? '#' . $node->getAttribute('id') : '')
                    . ($node->getAttribute('class') ? '.' . join('.', split(' ', $node->getAttribute('class'))) : '')
                    . ($node->getAttribute('name') ? '[name="' . $node->getAttribute('name') . '"]' : '')
                    . ($node->getAttribute('value') && strpos($node->getAttribute('value'), '<' . '?php') === false ? '[value="' . substr(str_replace("\n", '', $node->getAttribute('value')), 0, 15) . '"]' : '')
                    . ($node->getAttribute('value') && strpos($node->getAttribute('value'), '<' . '?php') !== false ? '[value=PHP]' : '')
                    . ($node->getAttribute('selected') ? '[selected]' : '')
                    . ($node->getAttribute('checked') ? '[checked]' : '')
            ;
        } else if ($node instanceof DOMTEXT) {
            if (trim($node->textContent))
                $return[] = 'Text:' . substr(str_replace("\n", ' ', $node->textContent), 0, 15);
        } else {
            
        }
    }
    return $oneNode && isset($return[0]) ? $return[0] : $return;
}

/**
 * Dump htmlOuter and preserve chain. Usefull for debugging.
 *
 * @return phpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
 *
 */
public function dump() {
    print 'DUMP #' . (phpQuery::$dumpCount++) . ' ';
    $debug = phpQuery::$debug;
    phpQuery::$debug = false;
//		print __FILE__.':'.__LINE__."\n";
    var_dump($this->htmlOuter());
    return $this;
}

public function dumpWhois() {
    print 'DUMP #' . (phpQuery::$dumpCount++) . ' ';
    $debug = phpQuery::$debug;
    phpQuery::$debug = false;
//		print __FILE__.':'.__LINE__."\n";
    var_dump('whois', $this->whois());
    phpQuery::$debug = $debug;
    return $this;
}

public function dumpLength() {
    print 'DUMP #' . (phpQuery::$dumpCount++) . ' ';
    $debug = phpQuery::$debug;
    phpQuery::$debug = false;
//		print __FILE__.':'.__LINE__."\n";
    var_dump('length', $this->length());
    phpQuery::$debug = $debug;
    return $this;
}

public function dumpTree($html = true, $title = true) {
    $output = $title ? 'DUMP #' . (phpQuery::$dumpCount++) . " \n" : '';
    $debug = phpQuery::$debug;
    phpQuery::$debug = false;
    foreach ($this->stack() as $node)
        $output .= $this->__dumpTree($node);
    phpQuery::$debug = $debug;
    print $html ? nl2br(str_replace(' ', '&nbsp;', $output)) : $output;
    return $this;
}

private function __dumpTree($node, $intend = 0) {
    $whois = $this->whois($node);
    $return = '';
    if ($whois)
        $return .= str_repeat(' - ', $intend) . $whois . "\n";
    if (isset($node->childNodes))
        foreach ($node->childNodes as $chNode)
            $return .= $this->__dumpTree($chNode, $intend + 1);
    return $return;
}

/**
 * Dump htmlOuter and stop script execution. Usefull for debugging.
 *
 */
public function dumpDie() {
    print __FILE__ . ':' . __LINE__;
    var_dump($this->htmlOuter());
    die();
}

}
